Counterweighted pitman



Jan. 16, 1934.

Filed Oct. 26, 1931 2 Sheets-Sheet 1 INVENTOR ATTORNEY Jan. 16, 1934. (5, w,- WALTON 1,943,906

COUNTERWEIGHTED PITMAN Filed Oct. 25, 1931 2 Sheets-Sheet 2 INVENTOR 680/26 WWa/fo/r BY ATTORNEY Patented Jan. 16, 1934 UNETED STTES ATENT FFEE COUNTERWEIGHTED PITMAN George W. Walton, Dallas, Tex.

Application October 26, 1931. Serial No. 571,163

10 Claims.

My invention relates to counterbalances and more particularly to apparatus of that character for counterbalancing well pumping mechanism during pumping and similar operations.

In order to counteract, to a certain extent, the combined weight of the sucker rod string and the weight of liquid supported by one end of the walking beam while liquid is being elevated from the well, various types of counterbalances have been provided on the opposite or pitman end of the walking beam, the majority of these weights being secured to the crank.

It has been found, however, that by mounting the counterweights on the pitman, the weights will be in a more direct line with the walking beam, thus producing a more satisfactory counterbalancing action.

A further advantage in thus mounting the counterweights is that the weights can be located at a more remote point from the crank shaft, thereby increasing their leverage.

The principal object of my invention, therefore, is to provide counterweights and means for readily attaching or detaching the weights to or from a pitman without necessitating removal of the pitman from the crank.

Another object of the invention is to provide simplified means for securing supplementary weights to the main counterweights.

In accomplishing these and other objects of my invention, I have provided improved details of structure, the preferred form of which is illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of apitman provided with a counterbalance embodying my invention and shown in operable relation with a crank and with a portion of a walking beam.

Fig. 2 is a perspective View of the lower end of a pitman and of the counterbalance shown in disassembled relation.

Fig. 3 is a perspective view of a counterweight body, and of a pair of supplementary weights in disassembled relation with the main weight.

Fig. 4 is a longitudinal central section of a main weight member.

Fig. 5 is a longitudinal cross section of a main weight on the line 55, Fig. 4, and of a supplementary weight secured thereto in functional relation.

Referring more in detail to the drawings:

1 designates a portion of a derrick floor whereon are mounted jack posts 2 rotatably support ing a crank shaft 3 carrying a band wheel 4 and a driven sprocket 5 operably connected with a suitable source of power by a chain 6.

(Cl. Vi-71) Fixed on the inner end of the shaft 3 is a vated thereby,.I have provided a counterbalance including an anchoring member 13 triangular in formation and having a comparatively thin web portion 14;. Extending outwardly from opposite faces of the web portion are aligning flanges 15 defining an angular opening 16 terminating at its upper end in a mouth 17 of less width than the maximum width of the angular opening.

A hearing block 18, conforming in shape to the angular opening, is provided with a bushing l9 for journalling the wrist pin, the bushing being preferably mounted in the block on roller or ball bearings to reduce wear. Spaced channel members 20 and 21 having edge flanges 22 di rected outwardly, or in opposite directions, are fixed to the bearing block by welding or the like, as indicated at 23, the channels being of sufficiently less width than the mouth 17 of the angular opening so that the pitman 9, which is preferably of I-beam construction, may be con- The Opposite end or t nected with the channel members, the web portion 24 of the pitman fitting between the spaced channel members and the outer flanges 25 of the pitman being mounted between the edge flanges of the channel and the outwardly directed flanges 15 adjacent the mouth opening 1'7.

Aligning openings 26, 27 and 28, in the flanges 15, 25 and 22 respectively, are adapted to receive bolts 29. for securing the channel members, pitman and flanges 15 of the anchoring member together, and rivets 30 are extended through aligning openings 31 and 32 in the channel members and pitman respectively to further secure the channel members to the pitman.

It will thus be noted that the anchoring memher is fastened very rigidly to the pitman and that this member may be readily dismounted from the bearing block and pitman by removing the bolts 29. The anchoring member thus constitutes an approximate equilateral triangle having its upper edge in a horizontal plane and its lower edges converging to a point in vertical alignment with the pitman.

The outer ends of the anchoring member terminate in forked arms 33 forming slots 34 be 7 tween the arms for receiving the anchoring bolts 35 of a pair of cooperating counterweights 36 now to be described in detail.

Each of the counterweight members includes an arcuate outer edge 37, an inclined inner edge 38 conforming to the lower edges of the anchoring member, and a vertical edge 39 complementary to the vertical end edges of the forked arms so that a counterweight positioned adjacent one of the lower edges of the anchoring member will snugly engage the member when connected therewith.

The counterweight members are each further provided with a socket 40 having a transverse bearing opening 41 for receiving a bearing bolt 42 extended through an eye 43 formed on the lower end of the anchoring bolt 35. A similar socket 44 is provided in each anchoring member adjacent its lower end and a bolt 45, extended transversely through openings 46 of the socket, is also extended through the eye 4'? of a tie rod 48 to hingedly connect the lower ends of the cooperating counterweight members.

Attention is further directed to the lower end edges 49 of the counterweight members which are adapted to assume an abutting relation when the counterweight members are dismounted from the anchoring member, as disclosed in Fig. 2, and rest on the derrick floor.

It will thus be noted that mounting of the counterweights on the anchoring member is a comparatively simple procedure, the apparatus being so designed that, by lowering the pitman with the anchoring member into approximate engagement with the counterweights supported on the floor, the bolts 35 may be moved between the slotted arms of the anchoring member and nuts 50 threaded thereon to elevate the counterweights into abutting engagement with the lower faces of the anchoring member.

Since the weight of the rod string and also the weight of the fluid column supported thereby, varies in proportion to the depth of a well, it is desirable to accordingly vary the counterbalancing weight applied to the pitman, and I have, therefore, provided for mounting supplementary weights 51 on the main counterweight members.

As illustrated in Fig. 3, the supplementary weights may be formed of any desired thickness and one or more of these weights may be attached to the original counterweight. While the supplementary weights are shown in the drawings as conforming in shape to the main weights, it will be apparent that this shape may be deviated from in order to effect a lag or lead action of the weights on the pitman.

To simplify attachment of the supplementary weights to the main weight, both weights are preferably provided with series of aligned openings 52 for receiving clamping members 53, each member including a central bolt 54 adapted to extend through the central openings of the series 52.

Guide pins 55 formed integrally with the clamping members in parallel relation with the bolts 54 extend through the outer openings of the series 52 to prevent excessive strain on the center bolt.

As is best illustrated in Fig. 5, the supplementary weight is firmly anchored to the main Weight by the clamping members, nuts 56 being threaded on the bolt for securing the members together and the guide pins serving to reduce the shearing strain on the bolts 54.

The heads of the bolts 42 projecting outwardly from the main anchoring members seat in sockets 5'7 formed in one face of the supplementary counterweights and it will be noted that if more than one supplementary weight is attached to a main weight, complementary bosses may be formed on one supplementary weight for seating in the recesses 57 of an adjacent weight to further assist in maintaining the weights in aligned condition.

The bearing block may be retained in assembled condition on the crank pin by a washer 58 and cotter pin 59.

Assuming a pitman and counterweight assembly to be constructed as described, the procedure for attaching the weights to a pitman and the operation thereof would be as follows:

With the channel members 20 welded to the bearing block as described, the anchoring member may be mounted on the block and moved into alignment with the channel members.

The lower end of the pitman is then seated between the channel members and between the flanges of the anchoring and channel members, and is secured thereto by rivets or bolts, as described.

A pair of cooperating counterweight members having their lower ends hingedly connected by a tie bolt 48 is then mounted on the derrick floor in alignment with the pitman. The bolts 35 are next moved between the forked arms of the anchoring member and the nuts threaded on the bolts to elevate the counterweights into abutting engagement with the lower faces of the anchoring member which will securely assemble the parts in functional condition.

If the weight of the counterbalance is insufficient to counteract the weight of the sucker rod string and well fluid, additional weight may be secured to the main counterweights by means of 1 the clamping members, as previously described.

As the pitman end of the walking beam moves upwardly, the opposite end carrying the rod string will be moving downwardly and the counterweights will add resistance to the travel of the walking beam in this direction. However, upon opposite rocking movement of the walking beam, when the well fluid must be elevated together with the additional weight of the sucker rods, the counterweights will be moving downwardly to assist in pumping fluid from the well.

If it is desired to remove the counterweights from the anchoring member, it is merely necessary to unthread the nuts from the bolts 35 until the counterweights rest on the derrick floor in the position indicated in Fig. 2, whereupon the bolts 35 may be moved out of engagement with the slotted arms 30.

From the foregoing it will be apparent that I 135 have provided an eflicient counterbalance and simplified means for mounting and dismounting the counterweights on a pitman of well pumping equipment.

What I claim and desire to secure by Letters Patent is:

1. A counterbalance for apparatus of the character described comprising, in combination with a pitman and a weight mounting member in fixed relation with the pitman, a pair of counterweights, hingedly connected together at their lower ends and means detachably securing the upper ends of the counterweights to said mounting member.

2. A counterbalance for apparatus of the charwcter described comprising, in combination with a pitman, a weight mounting member on the pitman, a counterweight including sections hingedly connected together, and means hinged to the counterweight sections for detachably securing the counterweight sections to the mounting member.

3. A counterbalance for apparatus of the character described comprising, in combination with a pitrnan, a weight mounting member on the pitman having seats for connecting members, a counterweight including sections hingedly connected together, and bolts hinged to the counterweight sections and cooperative with said seats to remo-vably secure the counterweight sections to the mounting member.

4:. A counterbalance for apparatus of the character described comprising, in combination with a pitman, a weight mounting member having seats for connecting members, means for securing said weight mounting member on said pitrnan, counterweight members having corresponding ends hingedly connected together and having sockets at their opposite ends, and bolts pivotally mounted in said sockets and cooperative with said seats to removably secure the counterweight members on said mounting member.

5. A. counterbalance for apparatus of the character described comprising, in combination with a pitman including a weight mounting member having seats for connecting members, counterweight members having sockets in their end portions, means secured in corresponding sockets in adjacent ends of said members for hingedly connecting the members, and bolts pivotally mounted in the sockets in the opposite ends of said counterweight members and cooperative with said seats for removably securing the counterweight members to the mounting member on the pitman.

6. A counterbalance for apparatus of the character described including, in combination with pitman, a weight mounting member on the pitman having downwardly converging side edges, a pair of counterweights hingedly connected at their lower ends and having interior flat faces, means removably retaining the counterweights on the mounting member with the fiat faces of the weights in engagement with the side edges of the mounting member.

'7. A counterbalance for apparatus of the character described including, in combination with a pitman, a weight mounting member on the pitman having downwardly converging side edges and seat members at the outer ends of said edges, a pair of counterweights hingedly connected together at their inner ends having interior flat faces and seat sockets at the outer ends of said faces for receiving said seat members, and bolts cooperating with the seat members to removably secure the counterweight to the mounting member.

8. A counterbalance for apparatus of the character described comprising, in combination with a pitman, an anchoring member on the pitman having forked arms, a pair of counterweights hingedly connected together at their lower ends, bolts pivotally connected to said weights adjacent their upper ends for swinging movement between said forks, and nuts threaded on the bolts for drawing the weights against said anchoring member.

9. A counterbalance for apparatus of the character described including, in combination with a pitman, an anchoring member on the pitman, a pair of counterweights hingedly connected together at their lower ends, means on the counterweights for limiting outward hinging movement of the weights, and means pivoted to the weights for removably securing the counterweights to the anchoring member.

10. A counterbalance for apparatus of the character described comprising, in combination with a pitman, an anchoring member on the pitman, a plurality of counterweight members, means for hingedly connecting said counterweight members together, and means hinged to each counterweight member for detachably securing said member to the anchoring member.

GEORGE W. WALTON. 

